Switch handle



Aug. 10 1926.

C. E. CANFIELD SWITCH HANDLE Fil ed .Nov. 21, 1921 //ll f Mi EvInventor. Ch arvles ECanfield,

HIS Aitorn ey.

Patented Aug'.- 10, 192 6.

:UNITED STATES PATENT orries.

CHARLES E. CANFIELD, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR: TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK. 4

SWITCH HANDLE.

My invention relates to tap changing switches for encased electricalapparatus such as transformers. It is frequently desirable to providesuch apparatus with a switch located with the apparatus inside a casingor container and electrically connect ed with a series of taps broughtout from the windings of the apparatus so that it may vary the number ofeffective turns of such windings. When used in connection with theprimary windings of. a transformer, such a switch may be usedto vary thevoltage ratio of the transformer by varying the number of effectiveturns in the primary winding and therefore the ratio between the primaryand secondary turns.

It is more particularly the principal object of the present invention toprovide an improved handle for a ratio adjusting switch such that thehandle may be located outside the casing or container 1n some convenientand accessible location, preferably by mounting it directly on the outersurface of the container; Apparatus oi the class re-, ferred to isfrequently immersed in an insulating and cooling fluid such as oil, theoil completely filling the container. A socalled conservator orreservoir located above the top out the fluid in the casing is oftenconnected with the space within the corn tainer and filled at leastpartially with the tluid so as to maintain the container full of thefluid at all times. It will be seen that with this arrangement, thefluid within the container is always under some pressure,

and it a further object of the invention to provide a ratio adjustingswitch handle so constructed that no cooling liquid may leak past itsjoints from within the con.

tainer. 1

One embodiment of my invention is illustrated in the accompanyingdrawing in which Fig. 1 is a plan view of a .ratio adjustingswitchhandle constructed in accordance therewith; Fig. 2 is anelevation,-partly in section on the line 2 of Fig. 1; and Fig. 3 is anelevation of a container, with the handle mounted thereon, for inductionap aratus,- such as a transformer.

n this embodiment of the invention, the induction apparatus and switchare surrounded by a casin or container 1 provided with a coverv 2. 'l iscover 2 forms a base torthe switch handle and has an opening 3surrounding which on the upper lace of the cover is a seat for a gasket4. Over the opening 3 is an annular member 5 secured against the gasket4 by screws 6. These screws 6 are s aced at difierent angular dis tancesabout t e periphery of the member 5 so that this member can be securedtothe cover 2 in only one position. A shaft 7 ex tends through thecentral opening of the annular member 5 and is surrounded by packingmaterial 8, such as asbestos, which is compressed and held in place by afollower 9 under a nut 10 screw-threaded into the upper end of thecentral opening in the annular member 5. An imperforate cap 11 coversthe top of the shaft 7 and the nut 10 and is held against the annularmember 5 by screws 12, a gasket bein provided between the opposing faces0 this cap and the annular member 5. A headedpin 13 passes throu h ahole in the upper end of the shaft 7, the hole in the shaft being smallat one end to lit the shank of the pin and larger at the other end tofit the head ot the pin so that the pin can be inserted in the shaftonly in one direction. The inner closely both ends of the pin 13 whichprotrudefrom the shaft as shown clearly in Fig. l. struction that thepin 13 constitutes means which ensures that the cap and shaft shallalways maintain the same relative angular positions and that they cannotbe otherwise assembled. The lower end of the shaft is connected to a rod14 by a stud 15 anda sleeve 16, these members being pinned togetherasshown in Fig. 2 and one or more of the joints being loosely pinned toallow a desirable amount of play between the shaft and rod. The rod 14extends to the ratio adjusting switch and is adapted to op-' crate oradjust this switch as it is turned.

The switch and the lower end of the rod are pointer 18 earned by. thecap 11 and movable over a series of figures or indicating lt willbeunderstood from this conmarks on the member 5, each of these marksindicating the position of the pointer for a corresponding switchadjustment. When a change in switch adjustment is desired, the twoscrews 12 are removed to release the cap 11 and the cap rotated untilthe pointer 18 indicates the desired adjustment. The two screws 12 arethen replaced and tightened, additional threaded holes 19 in the member5 being provided for the screws 12 so that thetap 11 may hold the switchin any desired operative adjustment as indicated by the pointer 18. Thegaskets between the cover 2 and member 5 and between the member 5 andthe cap 11 form seals which prevent any leakage of oil or other coolingfluid from within the handle and which might leak along the shaft 7. Thepacking 8 around this shaft will of course prevent any appreciableleakage duringsuch times as the cap may be loosened for the purpose ofadjusting the switch. Stops 20 and 21 formed on the periphery of the cap11 cooperate with a post or stop 22 on the member 5 to limit rotation ofthe cap. in either direction aeaeae beyond the limits of movement of theswitch.

What I claim as new and desire to secure by Letters Patent of, theUnited States, is

A switch handle including a base having an opening, an annular member,means for securing said annular member in one angular posltion only oversaid opening, aswitch operating shaft extending through said opening andsaid annular member, a stuffing box carried by said annular member topro vide a seal about said shaft, an imperforate cap over the end ofsaid shaft, means for securing said cap about the end of said shaft inone angular position only relative thereto,

seals between said cap and annular member and between said annularmember and base, means for securing said cap to said annularmember inditl'erent angular positions corresponding to different operativepositions of the switch controlled by said shaft, and

indicating means on said cap and annular member for indicating switchpositions.

In witness whereof, I have hereunto set my hand this 5th day of Now,1921.

CHARLES E. CANFIELD.

